Stefan Maus: They're equipped with very sensitive magnetometers that measure the direction and strength of the magnetic field and that altitude.
斯特芬?茅斯：科学家们采用非常灵敏的磁力计来测量地磁场的方向、强度及方位。
2
Source effects vary with field periods, resistivity, source altitude and observation location.
场源效应受场源高度、信号周期、电阻率、测点距离等的影响。
3
ESPI can measure the object, through forming a carrier pattern on the object surface (carrier pattern modulation), analyze the relation between displacement field and altitude of the object surface.